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You should take advantage of a wide variety of field days being offered in Virginia this year. Next week, Corbin Hall farm will host our largest annual event, the Virginia Ag Expo. Registration begins at 7:30 on Wed., August 13. This year's theme, Circle of Success, emphasizes how consistent interaction and communication among producers, equipment dealers, seedsmen, the crop protection industry, financial institutions, Cooperative Extension and other suppliers helps Virginia agriculture prosper.
Other events are listed in this newsletter. Try to attend.
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Ames Herbert,Extension Entomologist
In cooperation with: Mike Arrington, Sean Malone, Ken Bradshaw, Mike Ellis, Jonathan Burkett, Tom Kuhar, Jack Speese, Keith Balderson, Mac Saphir, David Moore, Glenn Chappell, Matt Lewis, Sam Johnson, Ginny Barnes and Paul Davis
Each summer in Virginia, a large group of helpers and volunteers (above) cooperate to sample field corn for corn earworm populations. This survey effort tells us how large that pest population is and what to expect in terms of pest pressure when that generation matures and moths fly to infest new host crops like soybean, cotton, peanuts, tomatoes and others. Over the years, survey results have been very accurate and helpful to growers in planning their pest management programs.
Our annual field corn survey has just been completed and based on the results; we are predicting moderate to high-moderate levels of corn earworm pressure in soybean and other host crops. These past few days, 6,900 ears were sampled from 138 fields in 27 counties. Overall, infestation levels were considerably lower compared with last year. Corn in the southeastern counties averaged almost 50% infested, compared with 75% last year. This indicates a moderate-to-high level of risk. Infestation levels were lower in all other regions and indicated only moderate risk. The Eastern Shore counties averaged 30% (compared with 48% last year), the mid-eastern counties 30% (compared with 50% last year), the Northern Neck 19% (compared with 45% last year), and the northern counties 25% (compared with 55% last year).
If you only remember one thing from this note, remember that we always hedge our prediction based on the weather conditions in August. That is, the outcome of next corn earworm generation will be heavily influenced by the amount of rainfall fields receive in August. In years with a lot of heavy rains, many of the pupae that are in the soil will drown, moths will not fly well, eggs and small larvae will wash off of plant leaves and stems, and predator populations will thrive all of which work to reduce pest numbers and could result in lower than predicted levels of pest pressure. If, on the other hand, weather turns dry, survivorship of all pest stages will increase and infestations could even exceed predictions.
The field corn survey also showed that this year's field corn crop is highly variable in terms of maturity. During the survey, we focus on sampling only those fields where ear silks are dark brown and dry.
In some counties, almost half of the fields still had green silks due to late planting. This will result in a long moth flight out of corn on time flights out of timely planted corn, and later flights out or later planted corn. This can create a frustrating scenario for growers, as they have to keep up their field scouting efforts for a longer than normal period of time. Some help will be available as we provide weekly moth activity reports through mid September when most crops mature past pest-vulnerable stages.
This year, corn earworm moth activity is being tracked using a series of 18 blacklight traps located throughout eastern Virginia. As of July 31, trap catch is beginning to increase. This is the first indication that moths are beginning to migrate from corn fields. There is no magic trap catch number indicating that earworms are in soybean fields, but when traps begin catching 30-50 corn earworm moths or more per night, consistently, we will begin emphasizing the need to begin field scouting efforts.
Look for weekly updates at http://www.vaes.vt.edu/tidewater/insectadvise/ .
We encourage everyone to scout your soybean fields and use thresholds to make any spray decisions. An excellent web site is available to help with your spray decisions. This is the corn earworm economic threshold calculator. It can be found at: http://www.ipm.vt.edu/cew/ .
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Due to what seemed to be a shift of Virginia's climate to one that resembles a rainforest, our double-crop plantings were strung out well into July. Fortunately, the wet soil conditions have resulted in pretty good stands. The good stands, good soil moisture, and continued rains should still offer the possibility of good yields. But, these late plantings are not without risk.
My main concern will be an early frost. On average in Virginia, a 5-day delay in planting will result in a 1-day delay in maturity. Therefore, a 3-week delay in planting will result in a 4-day delay in maturity; a 5 week delay (not uncommon this year) will result in a 7-day delay in maturity. While this doesn't seem like much, a maturity group 5 just barely makes it to physiological maturity when planted in a double-crop system. Physiological maturity is when at least one pod on the main stem has reached its mature color. This normally occurs in early- to mid-October, if soybeans were planted in June. That's also only about a week ahead of our average frost date. So, we need a normal or late frost.
A second risk is lack of growth. Our leaf area research clearly indicates that complete canopy coverage is needed by full flower in order to maximize yield. This will not likely happen; therefore yield potential will be reduced. Even so, the high soil moisture conditions should minimize this problem. I think that we'll have very good growth potential through August. High temperatures (>900) should be the only thing hindering vegetative growth. I've seen July-planted soybean yield as well as June-planted soybeans, when growth potential was good.
Still, these soybeans will not obtain a tremendous amount of growth. This will make them more susceptible to defoliating insects. We've found that double-crop soybeans are more susceptible to defoliating insects, unless they are able to produce a leaf area index (LAI) of 4.0. LAI is basically a measure of leaf area divided by ground area. In other words, an LAI of 4.0 is the equivalent of 4 sq. feet of leaves per sq. foot of ground. This basically represents complete canopy coverage. If LAI is less than 4.0, then every bite an insect takes out of the leaf of the soybean crop will reduce yield. Dr. Ames Herbert recently reduced the threshold defoliation levels in double-crop soybeans from 15% to 10% due to these new findings. Therefore, keep this in mind as you're scouting your fields for corn earworm. More information on identifying soybean fields at risk to leaf-feeding insects can be found in the Cooperative Extension Publication 444-203. This publication can be found on the web at: http://www.ext.vt.edu/pubs/entomology/444-203/444-203.html .
A final concern is corn earworm. The delay in maturity for these late-planted beans will place corn earworm-susceptible soybean pods later in the season when corn earworm numbers are higher. In other words, these July-planted soybeans may experience higher corn earworm numbers. Be especially vigilant in scouting these fields. Don't ignore them; we could still have pretty good yields from these late plantings.
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The above photograph was taken on Roundup-Ready soybeans recently sprayed with glyphosate. We were called to the field to evaluate the insect defoliation that you see. (LAI was above 5.0 in this field, therefore we felt that the soybeans would tolerate this defoliation without yield loss. Therefore, an insecticide application was not recommended.) However, upon arriving, the sporadic yellowing of the upper leaves was noticed. This might be confused with manganese (Mn) deficiency, but the inter-veinal yellowing common to that deficiency was not clearly evident. In addition, other factors that would indicate a Mn deficiency (high soil pH, field recently limed) were not there.
I've also saw another field with this injury recently. In both situations, the glyphosate was sprayed to large soybeans. In addition, growing conditions were excellent. Therefore, more glyphosate was probably absorbed and translocated. Only in one field was there a pattern; areas with spray overlap were showing more injury. However, in the rest of the field, yellowing was sporadic and located randomly throughout the field.
Is this injury a cause for concern? I do not think so. In most cases, the leaves will green back up in a few days to a week. My main concern is that you don't confuse this with Mn deficiency and make an unnecessary application
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But, don't fret. The Virginia Soybean Association will continue to deliver to our producers a high quality educational event. This event, currently labeled "The Virginia Soybean Association's Winter Educational Meeting" (title may change) will be held at the Williamsburg Hospitality House on Feb. 6, 2004. We had previously scheduled this for Jan. 30. We want to deliver to you a most informative program. If you would like to suggest topics of interest, please contact me. We will be forming a program committee later this month. So mark your calendar. We hope to see you there.
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Upon arriving at the field exhibit area, the group will have the chance to view over 30 corn and soybean plots. Products showcased include corn hybrids, soybean varieties, various seed treatments and inoculants, herbicide, and insect management strategies. Sixteen companies plus Virginia Cooperative Extension will have exhibits where attendees can obtain educational materials and exchange information. Participants will be able to move from exhibit to exhibit and interact with the various exhibitors at their own pace.
Field exhibitors include: Augusta Seed, Bayer CropScience, Chemgro Seeds, Delta & Pine Land Co., Doebler's Hybrids, Garst Seed Co., Gustafson, Hubner Seed, Monsanto, Mycogen Seeds, Nitragen, Pioneer - a Dupont Co., Royster Clark, Southern States, Syngenta/NK Brand Seed, T.A. Doebler Seeds, and Virginia Cooperative Extension.
Another stop on the tour will give attendees a special treat. Representatives from John Deere will give a presentation on one of the newest innovations in equipment technology, an auto-tracking navigation system that allows pinpoint accuracy in equipment guidance. This GPS-controlled guidance system has many advantages over the conventional marking devices such as a foam marker, and especially over visual estimations. It is even a step above a "light bar" in that it does the steering for the operator. It insures accurate placement and avoids overlap of lime, fertilizers, and chemicals. The system can also reduce operator fatigue and anxiety regarding fertilizer and pesticide application. The presentation will include an overview on the theory behind such a system and a demonstration of its accuracy. In addition, participants will be given the opportunity to drive a tractor equipped with the system (or if you prefer, let the tractor drive them).
General field tours will begin at 8 a.m. Buses will run every 20 minutes to and from the field exhibit area. The last bus leaving for the field plots will be at 11:00 am.
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Virginia Small Grain Association Annual Conference: New Kent High School, Aug. 18.
Soybean Field Day: Eastern Virginia AREC, Warsaw, Aug. 19.
Tidewater AREC Field Day: Hare Road Research Farm, Suffolk, Aug. 21.
Virginia Soybean Association Winter Educational Meeting: Williamsburg, Feb. 6, 2004.
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"Securing passage of the biodiesel tax incentive and other measures designed to encourage the use of the fuel is our top legislative priority for the year," stated ASA President and National Biodiesel Board (NBB) Director Ron Heck from his farm in Perry, Iowa. "Last night's vote put us one step closer to achieving our goal, and the ASA would like to extend a sincere thanks to our friends in the Senate who fought hard to make this happen."
After weeks of heated debate, the Senate voted 84 to 14 in favor of the 2002 version of the Energy Bill that provided a 1-cent reduction of the diesel excise tax per percentage of biodiesel blended with diesel up to 20 percent. The bill also includes a Renewable Fuels Standard that calls for the nation's fuel supply to increase its use of renewable domestic fuels, like ethanol and biodiesel, to 5 billion gallons in 2012.
Incentives increasing biodiesel demand will also boost the need for soybean oil, its primary feedstock, which in turn will raise the price of soybeans. There are other reasons why biodiesel is so important to our country, in addition to these economic benefits. Biodiesel is made primarily from soybean oil grown here in the U.S., so it lessens our country's dependence on foreign oil. With over 55 percent of the oil we consume coming from the highly unstable Middle East, renewables like biodiesel should become a larger portion of our nation's fuel supply.
There are environmental benefits of biodiesel production as well. Emissions of greenhouse gases and particulate matter would be significantly reduced by increased biodiesel use. An increased demand for biodiesel could also create thousands of jobs across the U.S. economy.
"Soybean-based biodiesel is good for farmers, good for the environment, and good for our country," proclaimed Heck. "Incentives designed to encourage people to use biodiesel is the right policy for our country, and, on behalf of the ASA, I applaud the Senate for taking a big step in this direction."
The U.S. House of Representatives approved -its Energy Bill earlier this year. The difference between the House and Senate Bills will be reconciled in a joint House/Senate Conference Committee. Conference is where the refinements made by the Senate Finance Committee to the biodiesel tax incentive contained in the 2002 Energy Bill are expected to be included. These refinements were made through the amendment offered by U.S. Senators Chuck Grassley (R-IA) and Blanche Lambert Lincoln (D-AR) during Finance Committee consideration of the energy tax package last April.
In addition to this change, the ASA will be seeking to include in the final Energy Bill other key biodiesel measures, such as those supported by Senators Kit Bond (R-MO), Jim Talent (R-MO), and Tim Johnson (D-SD) that would encourage the use of biodiesel in meeting federal requirements for government alternative fuel use.
"While the Senate vote was a huge victory for biodiesel, supporters of the ASA Biodiesel Campaign should know that anything could change once the bill goes to Conference. The ASA calls on soybean farmers across the land to thank their Senators who supported the bill and encourage them, as well as their Representatives in the House, to express their support for the inclusion of strong biodiesel provisions in the final Energy Bill," urged Heck.
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Sincerely,
David L. Holshouser
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